Retardation device



Marchy 30, 1926. 1,579,049

c. D. AINSWORTH RETARDATION DEVICE i Filed Marvl 19 1921 /4/ /f' p# Patented Mar. 30, 1226.

UNITED STATES 1,579,049 PATENT OFFICE.

CHESTER D. AINSWORTH, OF WOLLASTON, MASSACHUSETTS, ASSIGNOB., BY MESNE ASSIGNMENTS, T CONDIT ELECTRICAL MANUFACTURING CORPORATION, 0F BOS- TON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

BETRDATION nnvrcn.

Application led May 19, 1921. SerialNo. 471,004.

To all whom t may concern.' I

Be it known that I, CHESTER D. AINS- WORTH, a citizen ofv the United States, residing at lVollaston, in the county of Norfolk and State of Massachusetts, have invented an Improvement in Retardation Devices, of which the following is a specification.

This invention relates to retardation devices and particularly to an electrically-controlled retardation device adapted to delay the -control of an electric circuit and has for its object to improve the construction of retardation devices of the type set forth.

Fig. l is a sectional elevation of the invention applied to the overload coil of an elecu t'ric switch.

Fig. 2 is a view similar to Fig. 1 but with the movable elements thereof disposed in an attracted position.

Fig. 3 is a sectional elevation illustrating the relative Vposition of the various elements to provide a rapid return or resetting of the movable elements.

Fig. 4 is a sectional elevation of the movable elements of thedevice.

Fig. 5 is a section along line 5 5 of Fig. 4, and illustrating more particularly the fluid passages for obtaining rapid resetting of the device. j

Fig. 6 is a section along line 6-,6 of. Fig. 4 and illustrating more particularly the leak passage.

As here shown, the device embodying the invention is contained in thel receptacle 10 which may also contain the stationary and movable switch members, not shown, of an electric switch; and is immersed in the oil therein; andthe oil serves as the fluid acted upon by the movable elements of the device.

The retardation device includes the solenoid having the winding 11 disposed on the tube 12, which latter forms a cylinder. The upper end of the'tube is sealed by the plug 13 which constitutes the Aixed pole-piece of and is arranged to be a relatively closelslid- .65

ing tit in said tube'12 whereby to reduce oil leakage between it and said cylinder. Said sleeve is formed with an axial opening 17a in which said stem 16is loosely received; and said sleeve and stem are relatively movv able, movement of said sleeve upwardly on said stem being limited by engagement with a pin 19 carried by said stem, and movement of said sleeve downwardly on,said stem being limited'by engagment with the shoulder 70 vportion 16a ofsaid stem. It is not of especial importance that said sleeve be a closel sliding fit on said stem and it is desirable that the sleeve be freely movable thereon. Passages 20 of relatively large'cross sec-4 9 tion are formed in said stem a shortl distance above the face 16b of they shoulder 16" to establish free oil communication between said passage 18 and the main body of oilin the receptacle 10. n 85 The lower face 17b of said sleeve is normally adapted toI engagethe face 16b of the shoulder 16a of said stem, andthe contact is .adapted to be substantially oil tight whereby to prevent appreciable oil leakageoo 4through said passages 20 when the core is -moving' upward. Preferably, said faces are adapted to contact throughout their radial extent. It will be obvious that as said sleeve is moved into engagement with said face 16b or away therefrom to uncover said passages 20 the flow of oil through said passages will berestricted or permitted.

- A leakpassage 21 is formed in saidstem A below the shoulder portion 16* and said 100 passage extends from said passage 18 to the side of said stem. An adjustable capmember 22 is formed with a recess in which t the lower end of said stem is received and said -cap extends upwardly on said stem and is adapted to be substantially oil tight contact therewith. The tbp face 22" 'ofsaid cap-member is tapered :so that one portion of its side wall is higher than its it will be held rmly against theface 16b opposite rtion and the higher portion is adaptedwto extend above and cover said passage 21 and vthereby prevent flow of oil through when the cap is adjusted in proper position. It is obvious that as said capmember is rotated on the end of said stem, L

the opening of said passage will be gradually uncovered and that any desired extent of opening, and therefore the amount of restriction of flow of oil therethrough may be varied by a proper adjustment of said cap-member. Preferably the side wall of said cap-member' is provided with a witness mark 23 and the shoulder portion 16' of said stem is provided with a series of graduations 23EL which vmay indicate the time required for operation of the device in specific adjustments thereof.

Said cap-member is held in place by the screw 24 which extends through said member and is threaded in the k'end of said passage 18. A striking disc 25 maybe interposed between vthe head of said screw and said cap to engage the arm 25a when the piston 1s moved to its upper position and trip the switch or otherwise control an electric circuit. f

A stop-member 26 may be disposed below said core to support it in its normal or low position and said stop-member may be adjustable vertically in a well known manner to vary the current value at which the device will operate. Normally the cor-e is at its lowermost position and is supported upon the member 26 and the sleeve 17 is in contact with the face 161 of `the shoulder 16a of the stem 16 and free flowof oil through said stem is thereby prevented. When the solenoid winding 1s sufliciently energized the piston will be moved upwardly within thev tube 12 and oil will be forced out of the space above the piston through the passage 18 in said core and the-leak passage 21; and the rate of flow of oil and consequently the rate of upward movement of the core will be governed by the setting of the cap-member 22. When the core has moved upwardly suliciently to control the circuit and the solenoid becomes de-energized, the stem 16 will drop and the shoiilder portion 16-will be moved Ifrom contact with the sleeve to uncover the passages 20 and admit oil freely -into the space above the core; whereby the core will return rapidly by gravity to its normal position. AfterI the stem has ldescended to its low position Ythe sleeve 17 will-subsequently deis preferably so formed for the reason thatv of the shoulder 16EL of the stem by magnetic attraction, inasmuch as said` stem extends above said sleeve toward the fixed pole piece 13, and an oil tight contact with said shoulder is assured' thereby.

It is obvious that the invention may be incorporated in other structures without departing from the spirit of the invention.

I claim:

1.'A retardation device including a cylinder, and a vpiston therefor including a stem having a fluid passage therein which has an opening at the top of the stem and a second and lower opening inthe side of the stem, and a sleeve conformed with and 4movably .fitting within said cylinder and surrounding and free for axial movement o-n said stem to control fluid flow through said-fluid passage.

2. A `retardation device including a cylinder, anda piston therefor including a stem having a fluid passage therein which has an opening at the top of the stem and a. second and lower opening in the side of the stem, and a sleeve conformed with and movably fitting within said cylinder and surrounding and free for axial movement on said stem to cover and uncover said second opening.

3. A retardation device including a cylinder, and a piston therefor including a sleeve conformed with and movably fitting within said cylinder and a stem extended through an aperture in said sleeve and movably axially therein, said stem having a fluid passage therein which has an upper opening at the top of the stem above said sleeve anda lower V,opening in the side of the stem below said sleeve, said stem also having a shoulder portion below saidA lower opening, andvsaidl sleeve and shoulder cooperating vto form a valve to control Huid flow through said passage.

4. A retardation device including a cylinder and a'piston therefor including a sleeve movable in engagement with said cylinder and a stem extended through an aperture in said sleeve and n'novable therein, said stem having a fluid passage in it which has an upper opening inthe top of said stem and a. lower opening in the side of said stem, said stem having a shoulder portion below said lower opening arranged to cooperate with said sleeve to form a valve to control flow of fluid in said stem-passage, said stem also 'having a leak opening in communication with said passage and means. to vary the dimensions of said leak opening.

5. A retardation 4device including a cylv inder, and a piston therefor including a sleeve movable within said cylinder, a stem movable within an aperture in said sleeve and extended downwardly beyond said sleeve, said stem having a fluid passage therethrough which has an upper opening in the side of the stem and, a leak opening in the Side of the stem, said stem having av shoulder portion below said second opening, said shoulder and sleeve arranged to form a valve to control flow of fluid through said stem-passage, and a cap received on the lower end of said stem having its side wall extended upwardly and arranged to control the extent of opening of said .leak

opening.

6. A retardation device including a cylinder, and a. piston therefor including a sleeve movable within said cylinder, a stem movable within an aperture in said sleeve and extended downwardly beyond said sleeve, said stem having a fluid passage. therethrough which has an upper opening in the top of the stem and a second .opening in the side of the stem and a leak opening in the side of the stem, said stem having a shoulder portion below said second opening, said shoulder and sleeve arranged to form a valve to control flow of fluid through said stem-passage, an adjustable cap received on the lower end of said stem having its side wall extended upwardly and arranged to control the extent of' opening ofsaid leak opening, and means to lock said cap in adjusted position.

7. A retardation device including a cylinder, and a piston therefor including a sleeve movable within said cylinder, a stem movable within an aperture extended on both sides beyond said Sleeve, said stem having a passage extended from end to end of it with an' `upper and a lower opening in the side of the stem communicating with said passage, said stem having a shoulder portion disposed below said upper opening arranged to cooperate with said sleeve to form a valve to control flow of fluid through said opening, a cap disposed over the lower end of' said stem which has its yside wall extended upwardly and arranged to contro-l the extent of opening of said lower opening, and a screw passed through said cap and threaded in the lower end ot' said passage in said stem.

8. A retardation device including a solenoid having a tube comprising a cylinder, a fixed pole piece closing the upper end of said cylinder, and a piston for the cylinder including a n iagnctie sleeve movable in said cylinder, a magnetic stem movable in an aperture in said sleeve and extended beyond said sleeve in both directions, said stein having a fluid passage which has' an upper opening in the top of the stem and a lower opening in the side of' said stem` said stem having a shoulder portion below said lower opening arranged to cooperate with Said sleeve to form a valve to control fluid flow in said passage, said sleeve arranged niagnetically to be held in contact with said shoulder, and said stein having a leak opening communicating with said passage.

9. A retardation device having a cylinder, and a piston therefor having a sleeve movable'wvithin and in engagement with the cylinder, a stem movable in said sleeve having a fluid passage which has an upper opening in the top and a lower opening in the side of' the stem, said stem having a shoulder portion below said lower opening arranged to cooperate with said sleeve to forni a valve arranged to control fluid flow through said passage, and means to hold said stem and sleeve magnetically in contact.

10. A retardation device comprising a solenoid having a tube comprising a cylinder, a core piece fixed in the upper end of said cylinder, a piston including a stem of magnetic materia-l having a fluid passage therein which has an opening vthrough the upper portion of the stem and a lower opening in the side of the stem, -said stem having an enlarged head below said lower opening, and a sleeve of magnetic material movable in said cylinder and on said stem to cover and uncover the lower opening in the stem and engageable with the head of the stem to prevent flow of' fluid through the passage in the stem, said stem arranged to extend upward above said sleeve toward the fixed core piece in the cylinder.

In testimony whereof, I have signed my name to this specification. l

` CHESTER D. AINSWORTH. 

